Tag Archives: Diversity Reception

Shortwave Radio Diversity Reception

Shortwave radio diversity reception provides a way to combine several fluctuating signals and get a solid result. It provided the foundation for most radio news received in America for years.

During World War II, most countries around the world relied on Britain’s shortwave radio broadcasts for the latest news from Europe. In the days before transatlantic audio cables or satellites, distant news traveled fastest by radio. Networks in the America’s, Australia, New Zealand and elsewhere re-broadcast shortwave radio news domestically.

Getting reliable, good quality audio programs over shortwave is always a challenge because of fading. As signals bounce off the ionosphere, they split over multiple paths. Often they fade and flutter, sometimes significantly, as the nature of the layers change with time. Here are several examples of shortwave signals fading, so you know what it sounds like. Skywave radio signals are subject to complex patterns of travel and interference.

Eventually, domestic networks found a clever way to get better audio from these distant signals.

[…]Diversity reception works like this. Instead of one signal, you monitor several signals at once and blend them together. Harold Beverage and RCA pioneered work on shortwave radio diversity reception in 1920’s. Commercial solutions arrived by 1933. Typically, you would use three receivers with three different antennas, spaced 1,000 feet apart. When antennas are widely spaced, signals arrive with different fading. Just combine the signals and let the strongest signal dominate. As long as the fading is not correlated across all three antennas, improvement can be significant.

Diversity reception can be achieved in several ways. The most popular – spatial diversity – is described above. Other methods include frequency diversity – mixing together the same program received on several different channels.[…]

SWLing Post Search

Affiliate links

Many of you have suggested in the past that the SWLing Post join an affiliate links program.

The SWLing Post now participates in two affiliate advertising programs with two large retailers that still sell shortwave radios, the Amazon Services LLC Associates Program and the eBay Partnership, designed to provide a means for sites like ours to earn advertising fees by advertising and linking to these retailers of radio products. Many of our links now function as affiliate links. This means that by clicking on these links, a small percentage of the purchase price for goods you purchase from these sellers will help support our site’s running costs. We hope you understand, and are grateful for your support.

But please note that we will never create a post and product link explicitly to receive a commission. Additionally, we always try to include links to other retail options if they are available, as we support and freely advertise independent ham radio retailers. Thank you, too, for your support of these sites.